Identification of Antimycobacterial Natural Products from a Library of Marine Invertebrate Extracts
Kojo Sekyi Acquah,
Denzil R. Beukes,
Ronnett Seldon,
Audrey Jordaan,
Suthananda N. Sunassee,
Digby F. Warner,
David W. Gammon
Affiliations
Kojo Sekyi Acquah
Department of Chemistry, University of Cape Town, Cape Town 7701, South Africa
Denzil R. Beukes
School of Pharmacy, University of the Western Cape, Bellville 7535, South Africa
Ronnett Seldon
Drug Discovery and Development Centre, Department of Chemistry, University of Cape Town, Cape Town 7700, South Africa
Audrey Jordaan
SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
Suthananda N. Sunassee
Department of Chemistry, University of Cape Town, Cape Town 7701, South Africa
Digby F. Warner
SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
David W. Gammon
Department of Chemistry, University of Cape Town, Cape Town 7701, South Africa
Tuberculosis (TB) remains a public health crisis, requiring the urgent identification of new anti-mycobacterial drugs. We screened several organic and aqueous marine invertebrate extracts for their in vitro inhibitory activity against the causative organism, Mycobacterium tuberculosis. Here, we report the results obtained for 54 marine invertebrate extracts. The chemical components of two of the extracts were dereplicated, using 1H NMR and HR-LCMS with GNPS molecular networking, and these extracts were further subjected to an activity-guided isolation process to purify the bioactive components. Hyrtios reticulatus yielded heteronemin 1 and Jaspis splendens was found to produce the bengamide class of compounds, of which bengamides P 2 and Q 3 were isolated, while a new derivative, bengamide S 5, was putatively identified and its structure predicted, based on the similarity of its MS/MS fragmentation pattern to those of other bengamides. The isolated bioactive metabolites and semi-pure fractions exhibited M. tuberculosis growth inhibitory activity, in the range 2 and Q 3.
